Conventional monoscopes display systems are well known and comprise a cathode ray tube driven by a monoscope wherein a target electrode of aluminum has a pattern of characters deposited thereon in the form of carbon, which has a different secondary emission characteristic from the aluminum base material.
Under constant use such a monoscope will deteriorate in quality within a few thousand hours, and, in addition, the signal level output from the monoscope is relatively low and changes as the monoscope ages.